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Concept

Théorie de Kirchhoff

Publications associées (20)

Narrowband Optical Coupler Using Fano Interference in First Order Diffraction

Olivier Martin, Benjamin Gallinet, Giorgio Quaranta, Fabian Michael Lütolf

Light coupling in waveguides has been extensively investigated in a variety of contexts, from photonic integrated circuits to biosensing and near-eye displays for augmented reality. Here, narrowband diffraction is reported using a Fano interference effect ...

AMER CHEMICAL SOC2021

Diffraction artefacts from twins and stacking faults, and the mirage of hexagonal, polytypes or other superstructures

Cyril Cayron

Recently, a hexagonal phase has been reported in high carbon steels in several studies. Here, we show that the electron microscopy results used in these studies were erroneously interpreted. The extra-spots in the diffraction patterns and the odd contrasts ...

2020

Light pattern generation with hybrid refractive microoptics under Gaussian beam illumination

Toralf Scharf, Maryam Yousefi

The generation of wide-angle diffraction patterns can be done in different ways using either thin diffractive optical elements with small features sizes or arrays of microoptics with large optical paths that are thick diffractive optical elements. Our aim ...

2020

Simulation of microoptics under inhomogeneous illumination: Sinusoidal Phase Grating under Gaussian Beam Illumination

Toralf Scharf, Maryam Yousefi

Far field pattern generation is investigated for thick sinusoidal phase grating under a Gaussian beam illumination to obtain a high field of view. We compare the Fraunhofer approximation with the High-NA propagator and demonstrate that the Fraunhofer appro ...

IEEE2019

Design and Analysis of Binary Fan-out Gratings based on Step-Transition Perturbation Approach

Toralf Scharf, Dong Cheon Kim

Nowadays, diffractive optical elements are used for a variety of applications because of their high design flexibility, compact size, and mass productivity. At the same time, they require having high and complex optical functionalities such as a large numb ...

SPIE-INT SOC OPTICAL ENGINEERING2019

Resonant Waveguide Gratings for Color-Selective Diffraction

Giorgio Quaranta

Resonant waveguide gratings (RWGs), also known as guided mode resonant (GMR) gratings or waveguide-mode resonant gratings, are dielectric structures where these resonant diffractive elements benefit from lateral leaky guided modes and can operate from UV t ...

EPFL2019

On Simple Scattering and Diffraction Models using Point Cloud Maps for Channel Model or Coverage Predictions

Karol Jacek Kruzelecki

One of the several challenges for high capacity wireless communications is to find propagation models able to predict as easily and accurately as possible the propagation channel to assess the performance of wide-band wireless systems. An investigation of ...

IEEE2018

Metallized Gratings Enable Color Effects and Floating Screen Films by First-Order Diffraction

Olivier Martin

A new concept for generating visual effects with metallized gratings is introduced. Shadow evaporation of aluminum onto dielectric gratings is shown to produce strongly asymmetric color effects. Zero-order effects are combined with +/- first-order transmis ...

Wiley-V C H Verlag Gmbh2015

Absorption Enhancement in Solar Cells With Periodic Interface Textures of Asymmetric Shape

Christophe Ballif, Franz-Josef Haug, Karin Söderström

We investigate light scattering interface textures for solar cells with the intention to obtain a more fundamental understanding of the absorption enhancement. Therefore, we study simplified structures with the periodic interface texture of sinusoidal and ...

Ieee-Inst Electrical Electronics Engineers Inc2015

Towards an incoherent off-axis digital holographic microscope

Christian Depeursinge, Frédéric Montfort

We propose and experimentally demonstrate a system in which off-axis digital holographic microscopy is realized using a broadband illumination source. Single-shot holographic measurements are enabled, while the coherence noise is removed thanks to the broa ...

Spie-Int Soc Optical Engineering2015

Closed-form expressions for modeling diffraction at printed dipole-based FSS

Juan Ramon Mosig, Maria Garcia Vigueras

This paper presents analytical expressions to model the diffraction of plane-waves at planar 2-D distributions of printed dipoles. In contrast to other available analytical or quasi-analytical models, this approach rigorously captures the main underlying p ...

Ieee2013

Full field vertical scanning in short coherence digital holographic microscope

Christian Depeursinge, Christophe Moser, Etienne Cuche, Frédéric Montfort

In Digital holography Microscopes (DHM) implemented in the so-called "off axis" configuration, the object and reference wave fronts are not co-planar but form an angle of a few degrees. This results into two main drawbacks. First, the contrast of the inter ...

Optical Soc Amer2013

Quantitative phase noise in a two-color low coherence Digital Holographic Microscope

Christian Depeursinge, Christophe Moser, Frédéric Montfort, Zahra Monemhaghdoust

In digital holographic microscopy (DHM), the long coherence length of laser light causes parasitic interferences due to multiple reflections in and by optical components in the optical path of the microscope and thus degrades the image quality. The parasit ...

Spie-Int Soc Optical Engineering2013

Electro-switchable polydimethylsiloxane-based optofluidics

Andreas Vasdekis, Marilisa Romito

We report on the fabrication and characterization of a new generation of electro-switchable optofluidic devices based on flexible substrates, combined with the extraordinary properties of reconfigurable soft-materials. A conductive polydimethylsiloxane mic ...

Royal Soc Chemistry2012

Huygens-Fresnel diffraction and evanescent waves

Demetri Psaltis

Based on a modified Huygens-Fresnel principle valid in the near field, we analytically verify the exponential wave decay of evanescent waves. This field decay along the propagation direction can be considered as the result of interference between elementar ...

2011

Dual wavelength full field imaging in low coherence digital holographic microscopy

Christian Depeursinge, Christophe Moser, Frédéric Montfort, Zahra Monemhaghdoust

A diffractive optical element (DOE) is presented to simultaneously manipulate the coherence plane tilt of a beam containing a plurality of discrete wavelengths. The DOE is inserted into the reference arm of an off-axis dual wavelength low coherence digital ...

Optical Society of America2011

Phase Retrieval and Gaussian Beam Mode Decomposition of Gyrotron Beams

In this dissertation, we have developed the necessary basis for the characterization of the RF output of a gyrotron. The characterization includes the phase reconstruction and Gaussian beam mode decomposition. In order to analyze the phase reconstruction i ...

EPFL2010

Extended Focus Optical Coherence Microscopy : Theory and Application

Martin Villiger

Optical coherence tomography (OCT) is an interferometric imaging technique that can provide depth resolved cross-sectional views of biological tissue. OCT employs light with low temporal and yet high spatial coherence. The sample is illuminated point by po ...

EPFL2010

Instrument-independent specification of the diffraction geometry and polarization state of the incident X-ray beam

This work augments the proposal of Schwarzenbach & Flack [J. Appl. Cryst. (1989), 22, 601-605], who have advocated the use of a diffractometer-independent definition of the azimuthal angle

\psi

to specify the diffractiongeometry of a Bragg reflection. It ...

2009

Amplitude point spread function measurement of high NA microscope objectives by digital holographic microscopy

Pierre Marquet, Christian Depeursinge, Tristan Colomb, Florian Charrière, Mihaela Marian

We present here a three-dimensional evaluation of the amplitude point-spread function (APSF) of a microscope objective (MO), based on a single holographic acquisition of its pupil wavefront. The aberration function is extracted from this pupil measurements ...

2007